docs: def DemoDB(keys_per_column=None, **kwargs):
      """
      Provides an instance of DB that hooks up to the Chinook DB
      See http://chinookdatabase.codeplex.com/ for more info.
      """
      _ROOT = os.path.abspath(os.path.dirname(__file__))
      chinook = os.path.join(_ROOT, 'data', 'chinook.sqlite')
      return DB(filename=chinook, dbtype='sqlite', keys_per_column=keys_per_column, **kwargs)